Attachment of ceramic matrix composite panel to liner

ABSTRACT

A combined liner and panel for use in a gas turbine engine comprise a ceramic matrix composite panel having a plurality of extending members extending away from a face of ceramic matrix composite panel which will face hot products of combustion. A liner includes a plurality of spring members that apply a bias force biasing the extending members. The spring members bias the extending members on the panel in a direction away from the face of the panel which will face the hot products of combustion. A gas turbine engine, and a method of attaching a ceramic matrix composite panel to a liner are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/925,732, filed Jan. 10, 2014.

BACKGROUND OF THE INVENTION

This application relates to the attachment of a ceramic matrix compositepanel to a liner for use in a gas turbine engine.

Gas turbine engines are known and, typically, include a fan deliveringair into a compressor where the air is compressed. The compressed air isdelivered downstream into a combustion section where it is mixed withfuel and ignited. Products of this combustion pass downstream overturbine rotors and then exit through an exhaust nozzle. The exhaustnozzle may also be provided with an augmentor, which provides additionalcombustion downstream of the turbine rotors.

As can be appreciated, the combustor and downstream sections may seevery high temperatures. Thus, protective heat resistant liners areutilized. One type of liner relies upon a ceramic matrix composite panelwhich is attached to a metal liner.

There are challenges with attaching ceramic matrix composite materialsas they may be somewhat brittle.

SUMMARY OF THE INVENTION

In a featured embodiment, a combined liner and panel for use in a gasturbine engine comprise a ceramic matrix composite panel having aplurality of extending members extending away from a face of ceramicmatrix composite panel which will face hot products of combustion. Aliner includes a plurality of spring members that apply a bias forcebiasing the extending members. The spring members bias the extendingmembers on the panel in a direction away from the face of the panelwhich will face the hot products of combustion.

In another embodiment according to the previous embodiment, the springmembers include a spring ring received within the extending members.

In another embodiment according to any of the previous embodiments, theextending members are rings and the spring rings are received within theextending members.

In another embodiment according to any of the previous embodiments, thespring ring has a central slot such that it has two sides.

In another embodiment according to any of the previous embodiments, theliner has a plurality of apertures, each provided with a finger. Thefinger receives the spring members.

In another embodiment according to any of the previous embodiments, thespring rings have chamfers on at least one end to facilitate movement ofthe extending members onto the spring rings.

In another embodiment according to any of the previous embodiments, theapertures in the liner are C-shaped and surround the finger.

In another embodiment according to any of the previous embodiments, thespring members are separate from the finger and are fixed to the liner.

In another embodiment according to any of the previous embodiments, thespring members are fixed to the liner at a location beyond the fingers.

In another embodiment according to any of the previous embodiments, thespring members have a first end fixed to the liner, and a second endthat is in contact with the finger. The spring rings are intermediatethe first and second ends.

In another embodiment according to any of the previous embodiments, acentral web is formed on the spring between the first and second endsand is bowed away from the finger.

In another embodiment according to any of the previous embodiments, theextending members on the panel bias the spring rings away from a relaxedposition to create the bias force.

In another featured embodiment, a gas turbine engine comprises acombustor section and an exhaust section downstream of the combustorsection. A panel and liner combination is mounted at a location in thecombustor, or downstream of the combustor, with the combinationincluding a ceramic matrix composite panel having a plurality ofextending members extending away from a face of ceramic matrix compositepanel which will face hot products of combustion, and a liner, includinga plurality of spring members. The spring members apply a bias forcebiasing the extending members. The spring members bias the extendingmembers in a direction away from the face of the panel which will facethe hot products of combustion.

In another embodiment according to the previous embodiment, the springmember includes a spring ring received within the extending members.

In another embodiment according to any of the previous embodiments, theextending members are rings and the spring rings are received within theextending members.

In another embodiment according to any of the previous embodiments, theliner has a plurality of apertures, each provided with a finger. Thefinger receives the spring members.

In another embodiment according to any of the previous embodiments, thespring rings have chamfers on at least one end to facilitate movement ofthe extending members onto the spring rings.

In another featured embodiment, a method of attaching a ceramic matrixcomposite panel to a liner comprises providing a ceramic matrixcomposite panel having a plurality of members extending away from a faceof ceramic matrix composite panel which will face hot products ofcombustion, and a liner including a plurality of spring members. Theextending members on the panel slide onto the spring members on theliner to create a bias force.

In another embodiment according to the previous embodiment, the liner isformed with apertures. The extending members are moved through theapertures prior to being slid onto the springs.

In another embodiment according to any of the previous embodiments, theextending members are rings. The spring member includes a spring ring.The extending member ring is slid onto the spring ring.

These and other features may be best understood from the followingdrawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a gas turbine engine.

FIG. 2 shows a liner and panel combination which may be utilized at anumber of locations in an engine such as the FIG. 1 engine.

FIG. 3 shows a detail of the liner and panel combination.

FIG. 4 shows a detail of a panel.

FIG. 5 shows a detail of a backing plate.

FIG. 6 shows a detail of the assembled panel and backing plate.

FIG. 7 shows a further detail of the assembled panel and backing plate.

FIG. 8A shows a first step in assembling the panel and backing plate.

FIG. 8B shows a subsequent step.

FIG. 9 shows a detail of a spring finger.

DETAILED DESCRIPTION

FIG. 1 schematically illustrates a gas turbine engine 20. The gasturbine engine 20 is disclosed herein as a two-spool turbofan thatgenerally incorporates a fan section 22, a compressor section 24, acombustor section 26 and a turbine section 28. Alternative engines mightinclude an augmentor section (not shown) among other systems orfeatures. The fan section 22 drives air along a bypass flow path B in abypass duct defined within a nacelle 15, while the compressor section 24drives air along a core flow path C for compression and communicationinto the combustor section 26 then expansion through the turbine section28. Although depicted as a two-spool turbofan gas turbine engine in thedisclosed non-limiting embodiment, it should be understood that theconcepts described herein are not limited to use with two-spoolturbofans as the teachings may be applied to other types of turbineengines including three-spool architectures.

The exemplary engine 20 generally includes a low speed spool 30 and ahigh speed spool 32 mounted for rotation about an engine centrallongitudinal axis A relative to an engine static structure 36 viaseveral bearing systems 38. It should be understood that various bearingsystems 38 at various locations may alternatively or additionally beprovided, and the location of bearing systems 38 may be varied asappropriate to the application.

The low speed spool 30 generally includes an inner shaft 40 thatinterconnects a fan 42, a first (or low) pressure compressor 44 and afirst (or low) pressure turbine 46. The inner shaft 40 is connected tothe fan 42 through a speed change mechanism, which in exemplary gasturbine engine 20 is illustrated as a geared architecture 48 to drivethe fan 42 at a lower speed than the low speed spool 30. The high speedspool 32 includes an outer shaft 50 that interconnects a second (orhigh) pressure compressor 52 and a second (or high) pressure turbine 54.A combustor 56 is arranged in exemplary gas turbine 20 between the highpressure compressor 52 and the high pressure turbine 54. A mid-turbineframe 57 of the engine static structure 36 is arranged generally betweenthe high pressure turbine 54 and the low pressure turbine 46. Themid-turbine frame 57 further supports bearing systems 38 in the turbinesection 28. The inner shaft 40 and the outer shaft 50 are concentric androtate via bearing systems 38 about the engine central longitudinal axisA which is collinear with their longitudinal axes.

The core airflow is compressed by the low pressure compressor 44 thenthe high pressure compressor 52, mixed and burned with fuel in thecombustor 56, then expanded over the high pressure turbine 54 and lowpressure turbine 46. The mid-turbine frame 57 includes airfoils 59 whichare in the core airflow path C. The turbines 46, 54 rotationally drivethe respective low speed spool 30 and high speed spool 32 in response tothe expansion. It will be appreciated that each of the positions of thefan section 22, compressor section 24, combustor section 26, turbinesection 28, and fan drive gear system 48 may be varied. For example,gear system 48 may be located aft of combustor section 26 or even aft ofturbine section 28, and fan section 22 may be positioned forward or aftof the location of gear system 48.

The engine 20 in one example is a high-bypass geared aircraft engine. Ina further example, the engine 20 bypass ratio is greater than about six(6), with an example embodiment being greater than about ten (10), thegeared architecture 48 is an epicyclic gear train, such as a planetarygear system or other gear system, with a gear reduction ratio of greaterthan about 2.3 and the low pressure turbine 46 has a pressure ratio thatis greater than about five. In one disclosed embodiment, the engine 20bypass ratio is greater than about ten (10:1), the fan diameter issignificantly larger than that of the low pressure compressor 44, andthe low pressure turbine 46 has a pressure ratio that is greater thanabout five 5:1. Low pressure turbine 46 pressure ratio is pressuremeasured prior to inlet of low pressure turbine 46 as related to thepressure at the outlet of the low pressure turbine 46 prior to anexhaust nozzle. The geared architecture 48 may be an epicycle geartrain, such as a planetary gear system or other gear system, with a gearreduction ratio of greater than about 2.3:1. It should be understood,however, that the above parameters are only exemplary of one embodimentof a geared architecture engine and that the present invention isapplicable to other gas turbine engines including direct driveturbofans.

A significant amount of thrust is provided by the bypass flow B due tothe high bypass ratio. The fan section 22 of the engine 20 is designedfor a particular flight condition—typically cruise at about 0.8 Mach andabout 35,000 feet. The flight condition of 0.8 Mach and 35,000 ft, withthe engine at its best fuel consumption—also known as “bucket cruiseThrust Specific Fuel Consumption (‘TSFC’)”—is the industry standardparameter of lbm of fuel being burned divided by lbf of thrust theengine produces at that minimum point. “Low fan pressure ratio” is thepressure ratio across the fan blade alone, without a Fan Exit Guide Vane(“FEGV”) system. The low fan pressure ratio as disclosed hereinaccording to one non-limiting embodiment is less than about 1.45. “Lowcorrected fan tip speed” is the actual fan tip speed in ft/sec dividedby an industry standard temperature correction of [(Tram ° R)/(518.7°R)]^(0.5). The “Low corrected fan tip speed” as disclosed hereinaccording to one non-limiting embodiment is less than about 1150ft/second.

FIG. 2 shows a duct 80 which is provided with a plurality of holes 86 toreceive studs or bolts 84 from a combined CMC panel and backing liner82. The panel 88 will face hot products of combustion in an engine suchas the FIG. 1 engine, while the duct 80 is a housing structure withinthe gas turbine engine.

The combined panel and liner 82 includes a ceramic matrix compositepanel 88 and a backing metal liner 90. The combination 82 can be locatedin a combustor, an exhaust nozzle, in an augmentor, or in any otherlocation within a gas turbine engine which sees hot products ofcombustion.

FIG. 3 shows the combination 82. As shown, the panel 88 has rings 92which are mounted on spring fingers 94 fixed to the liner 90. The springfingers 94 provide a bias force biasing the ceramic matrix compositepanel 88 onto the liner 90 and securely holding it, but not providing aforce high enough to fracture the ceramic matrix composite material.

FIG. 4 shows a detail of the panel 88 and the rings 92 which extend awayfrom one face of the panel 88. It should be understood the rings 92extend away from a face 93 which is on an opposed side of the panel 88relative to a face 95 which will face the hot products of combustion.

FIG. 5 shows a detail of the liner 90. As shown, there are a pluralityof apertures 96, each defining a C-shaped opening around an intermediatefinger 98. FIG. 6 shows the rings 92 received outwardly of a ring 104 ona spring finger 94. The spring finger 94 sits on the liner finger 98.

As shown in FIG. 7, the spring finger 94 has a remote end 102 which isattached, such as by welding, to the liner 90, preferably, at a locationbeyond the ends of the aperture 96. An opposed end 99 of the finger isspaced by a central web 100 which extends away from an inner face 101 ofthe liner 90, such that there is a bow in the spring 94. The remote end99 is free to slide along the finger 98 at the opposed end. As can beseen, a portion of the slot or aperture 96 is forward of a forward end111 of the finger 98.

When the spring ring 104 is received within the extending member orpanel ring 92, the ring 104 is biased downwardly toward the face 101 ofthe liner 90. This creates a bias force biasing the ring 92 and, hence,the liner 88 in a direction which is upward in FIG. 7, or away from thehot products of combustion which will be toward the face 95 of the panel88.

FIG. 8A shows a first step in assembling the panel 88 to the liner 90.As shown, the ring 92 is inserted through the aperture 96. In thisposition, the ring 104 is free. As shown in FIG. 8B, the rings 92 arethen moved to then be over the ring 104 and bias the ring 104 downwardlyas shown in FIG. 7. This creates a bias force as described above.Although FIG. 8B shows the panel 88 being the portion that is actuallymoved to have ring 92 slide onto ring 94, it should be understood thatthe opposite direction of movement, with the panel 90 being moved suchthat ring 104 is moved within ring 92 would also be possible. Eitherdirection would be met by the description of sliding the ring 92 ontothe ring 104.

FIG. 9 shows a detail of the spring 94. As shown, chamfers 106 and 108may be formed at ends of the ring 104 to facilitate the sliding of thering 92 into rings 104. In addition, there is a circumferentiallycentral slot 105 creating two discontinuous sides which assists increating a spring force from the rings 104 to be transferred into thecentral web 100 and the end 99.

The combined liner and panel 82 for use in a gas turbine engine has aceramic matrix composite panel 88 having a plurality of extendingmembers or rings 92 extending away from a face 95 of ceramic matrixcomposite panel 88 which will face hot products of combustion. The liner90 includes a plurality of spring members 94 that apply a bias forcebiasing the extending members 92. The spring members 94 bias theextending members 92 on the panel in a direction away from the face 95of the panel which will face the hot products of combustion. While rings92 are disclosed, other extending members may be utilized.

Although an embodiment of this invention has been disclosed, a worker ofordinary skill in this art would recognize that certain modificationswould come within the scope of this invention. For that reason, thefollowing claims should be studied to determine the true scope andcontent of this invention.

The invention claimed is:
 1. A combined liner and panel for use in a gasturbine engine comprising: a ceramic matrix composite panel having aplurality of extending members extending away from a face of the ceramicmatrix composite panel which will face hot products of combustion; aliner including a plurality of spring members, said spring membersapplying a bias force biasing said extending members, said springmembers biasing said extending members on said panel in a direction awayfrom said face of said panel which will face the hot products ofcombustion; wherein each of said spring members includes a spring ringreceived within said extending members; wherein said extending membersare rings and; and wherein said liner has a plurality of apertures, eachprovided with a finger and said finger receiving said spring members. 2.The combined liner and panel as set forth in claim 1, wherein saidspring ring of each of said spring members has a central slot such thatsaid spring ring of each of said spring members has two sides.
 3. Thecombined liner and panel as set forth in claim 1, wherein said springring of each of said spring members having chamfers on at least one endto facilitate movement of said extending members onto said spring ringof each of said spring members.
 4. The combined liner and panel as setforth in claim 1, wherein said apertures in said liner are C-shaped andsurround said finger.
 5. The combined liner and panel as set forth inclaim 1, wherein said spring members are separate from said finger andare fixed to said liner.
 6. The combined liner and panel as set forth inclaim 5, wherein said spring members are fixed to said liner at alocation beyond said fingers.
 7. The combined liner and panel as setforth in claim 6, wherein said spring members have a first end fixed tosaid liner, and a second end which is in contact with said finger, withsaid spring ring of each of said spring members being intermediate saidfirst and second ends.
 8. The combined liner and panel as set forth inclaim 7, wherein a central web is formed on said spring members betweensaid first and second ends and is bowed away from said finger.
 9. Thecombined liner and panel as set forth in claim 1, wherein said extendingmembers on said panel biases said spring rings away from a relaxedposition to create the bias force.
 10. A gas turbine engine comprising:a combustor section and an exhaust section downstream of said combustorsection with a panel and liner combination mounted at a location in saidcombustor, or downstream of said combustor, with the panel of thecombination comprising a ceramic matrix composite panel having aplurality of extending members extending away from a face of the ceramicmatrix composite panel which will face hot products of combustion, andthe liner of the combination including a plurality of spring members,said spring members applying a bias force biasing said extendingmembers, said spring members biasing said extending members in adirection away from said face of said panel which will face the hotproducts of combustion; and each of said spring members includes aspring ring received within said extending members, said extendingmembers are rings and said spring rings are received within saidextending members, and said liner has a plurality of apertures, eachprovided with a finger and said finger receiving said spring members.11. The gas turbine engine as set forth in claim 10, wherein said springring of each of said spring members having chamfers on at least one endto facilitate movement of said extending members onto said spring ringof each of said spring members.